Treatment of materials containing tantalum and niobium



Patented Apr. 30, r

or m'ramats comma Belgium,

lnrgique de TANTALUM AND NIOBIUH Pierre. Leemans, Hobokcn-les- Anvcrl.

asllgnor to Sccit. Genes-ale Metal- Boboken,

Hobokc'n-lel-Anverl,

Belgium s Belgian limited company 1938. Serial N0. 187,245.

. Original application January 27,

Divided and this anpllcation Apfll I, 1989, Serial-No. 66,536. In Great Britain March, 1937 1 Claim. oi is-1c) This application is a division of my application Serial No. 187,245 filed Jan, 2 ,1938.

This invention relates to an improved process for the recovery of tantalum and niobium from their ores, or from metallurgical by-products such as those in which the said elements are found in the form of oxide compounds, or

combined.

This invention has iorits object the recovery I Q by an economical process-oi'tantalum and niobium in the form of metals or of alloys. The present invention consists in the combination of a reducing operation of the primary material by means of one or several of the metals aluminium, calcium, magnesium, with a, subsequent reducing operation in an electric furnace of the slag obtained from the first said reducing operation, so as to obtain on the one hand a tantalum and niobium alloy and on the other hand a slag poorin tantalum and niobium.

The first reducing operation in the presence of one or more of the metals Al, Ca, Mg is car-\ 'ried out without other external heat than that required-for starting the reaction. In this way a slag comparatively rich in Ta and Nb is obtained. The said first reducing operation is carried out in the presence of the metals with which it is desired to alloy the tantalum and niobium, for

instance with iron. I! the said metal is not prescut in a suiiicient amount in the primary material, it is added in the metal or oxide form, so asto obtain the required tantalum and niobium alloy, for instance term-tantalum and ferroniobium. g

The second reducing operation, of the slag comparatively rich in Ta and Nb in an electric furnace, may be carried out in the presence 01' reducing agents, such as Ca, Al, Mg used either separately, or together, or by two.

According to another feature of the present invention, the primary material is subjected to a a ing one or several of the metals Ca, Al, Mg is melted in an electric furnace, of the Hroult type for instance, in the presence of the primary matantalum together, when both are present. in the terial containing oxides of Ta and/or Nb, wi the addition oi aflux such as C80, 510:, fluorspar, etc. A-slag is thus formed which acts upon the reducing metals or the ferro-Ta/Nb. The niobium is reduced and passes int'oan alloy, whilst the oxides oi the reducing metals pass into the slag. The slag is tapped as soon as it is exhausted or suiiiciently poor in A second slag containing the oxides of Ta+Nb is then produced from the" ferro-Ta+Nb and 19 tapped after being deprived substantially of its Nb. This operation is continued aslong as there is a sun icient amount of reducing metals leit in. the terro-Ta+Nb.

According to another feature of the invention, the primary material is subjected to a reducing operation with one or more of the elements Al, Ca, Mg, alloyed or combined with one or more metals as characterized below, in order to substantiallyseparate the whole or the major part oi the niobium or tantalum when one alone of said elements is present, or the niobium and form of alloy.

The metals which are added to the reducing agents are such metals whose alloying or combination reaction with the aforesaid reducing agents develops heat so that the metallothermlc power 01' a given quantity of these reducing elements is smaller in the obtained alloy or combination than the same quantity in the elementary state. Among these metals, nickel, cobalt, iron, are more particularly contemplated.

The raw material containing the tantalum and/or niobium may be subjected inside any suitable metallurgical apparatus, for instance in an electric furnace, to a reducing operation, with on of the elements nickel, cobalt, iron;

2-a slag rich in tantalum and/or niobium,

' which may be treated by any known process for the recovery of tantalum and/or niobium.

According to another feature of the invention, the primary material is subjected to a selective reduction in 'the'presence of one, or several or the. following reducing elements: Ca, Al, M8, alloyed or combined with one or more metals as characterized below,'so as to obtain a product as,

ments is smaller in the obtained-alloy or combination than the same quantity in the .ele-

mentary state. Among these metals, nickel, cobalt, iron, are more particularly contemplated.

For carrying this feature of the invention into efiect, the primary material containing tantalum and niobium may be subjected inside a suitable metallurgical apparatus, such as anelectricf furnace, to a selective reductionin'the presence of one or more of the elements Ca, Al, Mg, the thermic capacity of which has been diminished by. alloying or combining them to other metals sufliciently small to produce an alloy rich in such as, Ni, Co, Fe. The amount of reducing agent may so calculated that the major part ofthe Nb contained by the primary material .is reduced and passes into an alloy in which the ratio Nb/Ta is higher than that of the-primary material. The other component elements or the terial, and also a slag is obtained in which the ratio Ta/Nb is higher than that of the primary material. The slag maybe treated by any suitable known process with aview; to :recovering the tantalum and niobium; I I claim: v

A process for the treatment of primary materials containing the-metals tantalum and niobium inoxi'de form and another metal, such as iron, with a View to recovering separately an alloy rich in niobium and poor in silicon and carbon, and an alloy rich in tantalum and poor in silicon, comprising the steps of subjecting the primary materialvflrst to a reducing operation withoutexternal heat'bther than that required for starting the. reaction and by means of an amount of reducing'agent consisting of at least one or the metals Al, Ca, Mg. which amount is niobium and a slag comparatively rich in tantalum and niobium, separating the alloy rich in niobium from the slag thus produced and subiecting the slag to areducing operation inside an electric furnace in. the-presence of at leastone of the metals Al, Ca, Mg, to produce an alloy .rich in tantalum and a. second slag, and separating the alloy rich in tantalum from the second slag, as and for the purpose set forth.

JOSEPH PIERRE LEEMANS. v 30 

